1. Field of the Invention
The present invention relates to an arc spot welding equipment utilizing an industrial robot and more particularly to an arc spot welding equipment for use in an automatic welding of small works.
2. Description of the Prior Art
Resistance welding or arc welding is used for welding various brackets and other works to objects such as automotive floors and the like.
In the resistance welding, a work 2 is positioned by a jig 1 and applied to an object 3 and a spot welding is performed by means of a resistance welder 4, as shown in FIG. 1 and FIG. 2, or a swing type jig 5 is used to hole the work 2 and welding is performed, as shown in FIG. 3. Consequently, the welding equipment becomes large-scaled and equipment cost increases. Increase of the equipment scale not only leads to a large loss of space but also is disadvantageous in the aspect of work management. Also in the aspect of maintenance such an increased equipment scale incurs a serious loss. Besides, there arises a problem such that in case the shape of the object is changed because of a model change of the automobile or the like to which the work is attached, it is difficult to utilize the same equipment as that used in the former model.
On the other hand, in the arc welding, a work 7 is held and positioned relative to an object 8 by means of a jig 6 and then arc welding is performed by a welding torch 9, as shown in FIG. 4. Thus, a work positioning device is needed and a large-scale jig must be provided, resulting in increase of the equipment cost and a large loss in the maintenance of the equipment. Besides, in the event of a model change as referred to above, it is difficult to utilize the jig used before the model change as that to be used after the model change. Furthermore, the operation for setting the work to the jig is mostly performed manually by the operator, and the automation therefor is scarcely realized.